High-pressure piston or reciprocating compressor or the like



0. SGHAER May 27, 1930.

HIGH PRESSURE PISTON OR REOiPROCATING COMPRESSOR OR THE LIKE 2 Sheets-Sheet 1 Filed Feb. 29. 1928 y 7, 1.930. c. SCHAER 1,760,213

HIGH PRESSURE PISTON OR RECIPROCATING COMPRESSOR OR THE LIKE Filed Feb. 29, 1928 2 Sheets-Sheet 2 :7 E- 5 l I 28 I 5 25 24 E 51 Patented May 27, 1930 uurrs STATES PArEr CHARLES SCHAER, OF LANGENTHAL, SWITZERLAND, ASSIGNOR TO THE FIRM OF SULZER FRERES SOCIETE AHONYIVIE, F WINTERTHUB, SWITZERLAND HIGH-FRESSURE PISTON (3R RECIPROGATING COMPRESSOR OR THE LIKE Application filed February 29, 1928, Serial No.

This invention relates to multi-cylinder high pressure piston or reciprocating compressors or the like of the kind in which the driving apparatus drives one or more compressor pistons or intermediate pistons connected thereto, through the medium of an oscillating column of liquid.

According to the present invention means are provided for by-passing part of the liquid column in order to put one or more of the cylinders out of operation without stopping the action of the remaining cylinders. For example, one or more of the cylinders may be put out of operation by means of a by-pass device capable of being closed at will. In compressors in which some of the cylinders are driven mechanically and others through an oscillating liquid column, the hydraulically driven cylinders can be put out of operation by means of a pipe serving to by-pass part of the liquid column, the plpe being provided with a valve or suitable controlling member, which, preferably, can only beopened when the crank of the driving machine or of the driving piston is at or near its dead point so as to prevent damage to the driving pistons due to premature opening of the by-pass pipe.

The invention is particularly applicable to compressors of the above type in which the driving pistons are exposed on both faces to the column of liquid. v

A few constructional examples of the invention are illustrated diagrammatically by way of example in the accompanying drawings, in which Figure 1 shows a section of a three-stage hydraulically driven reciprocating compressor,

Figure 2 shows a diagram of a four-stage compressor of which some stages are driven mechanically and some hydraulically,

Figure 3 shows a section on the line aa of Figure 2, the hydraulically driven stages of Figure 2 being shown on a. larger scale,

Figure 3 is a part'sectional view showing amodification of the structure illustrated in Figure 3, and

' Figure 4 shows one stage of a compressor, comprising four cylinders.

257,888, and in Switzerland October 21, 1927.

In the construction illustrated in Figure 1 the piston 5 of the driving machine, which has a single-acting and a double-acting portion, is connected by the piston rod a to the cr osshead 3, driven by the crank 1 and connecting rod 2. The compressor pistons 6, 7 and 8 of stages I, II and III are connected to their respective intermediate pistons 9, l0 and 11 by couplings 12 and are actuated by liquid columns 13, 1 1 and 15. A by-pass 16 is provided between the liquid columns 14 and 15 and can be opened or closed by means of a valve 17. In this manner knocking of the pistons 9, 10 and 11 is prevented in the case of premature opening ofthe by-pass 16.

If, for example, the stuffing box 18 of the third stage has become leaky and must be re placed it is not necessary to stop the first stage. By opening the valve 17, shown in the closed position in Figure 1, the liquid column 15. is forced through the by-pass pipe 16 in the direction of the arrow 19 and fills the vacuum formed in the column 14: by the forward movement of the primary piston 5 without the intermediate piston 11 being moved. on the return movement of the piston 5 the liquid column 14 is diverted in the direction ofthe arrow 20 without the intermediate piston 10 being moved.

One advantageous result of an apparatus made in accordance'with this invention is clearly shown in the diagram forming Figure 2. In this arrangement stages IV, V, VI and VII, for example, are driven by the same crank 1, the fourth and fifth stages being mechanically driven while the sixth and seventh stagesare actuated by the driving machine through the medium of an oscillating liquid column. If nowas generally occurs, a repair or replacement of the packings is to be effected in the highest stage, it is not necessary to stop the whole compressor, but the fourth and fifth stages may continue to operate, the by-pass member, provided according to the invention, only putting out of operation the compressor pistons of the sixth and seventh stages, the corresponding reserve set dealing with the delivery while these stages are inoperative.

machine (Figure 3) acts on the liquid columns 22 and 23 which actuate the compressor pistons 27 of the sixth and 28 of the seventh stages connected to the intermediate pistons and 26 respectively.

The cylinders containing the pistons 25 and 26 are connected by a pipe 24, containing a coupling column to which the liquid columns 22 and 23 are respectively connected by means of by-pass pipes 29 and 31, provided with valves 30 and 32. In order to put the sixth and seventh stages out of action itis only necessary to move the valves 30 and 32 into the open position shown, whereupon when the piston 5 moves in the direction of the arrow 33, the liquid from-the column 22 flows back through the bypass 31 into the pipe 24 and thence through the by-pass 29 into the column 23. When the piston 5 moves in the direction of the arrow 34, the liquid from the column 23 flows through the by-pass 29 into the pipe 24 and thence through by-pass 31 and back into I the column 22, without actuating the intermediate pistons. If, for example, only stage VII is to be cut out, the valve 30 is closed, when the liquid instead of acting on the piston 26, flows into the pipe 31 during the pressure stroke of the piston 5 (arrow 33). On the return stroke of the piston 5 this liquid again flows back through the pipe 31 so that the piston 26 and the compressor piston 28 connected thereto, remain stationary.

A modification is shown in Fig. 3*. In this modification the column 22 is connected to the column 23 through a by-pass 35 which may be closed by means of a stop valve 36 shown in open position.

In addition to the advantages already set forth, further advantages are obtained which will be explained later with reference to Figure 4.

In the construction illustrated in Figure 4, the pistons 40 and 41 of thedriving machine, mounted on the piston rod 4, are driven by the crank 1 and actuate the compressor pistons 52, 53, 54 and 55, connected to the intermediate pistons 48, 49, 50 and 51, through the medium of liquid columns 44, 45, 46 and 47. The upper faces of the intermediate pistons are connected together by coupling liquid columns 42 and 43.

Between the coupling column 43 and the driving columns 44 and 45 are provided bypass pipes 58 and'59 having stop valves 56 and 57. Other by-pass pipes 60 and 61 having control valves 62 and 63' respectively are provided between thecoupling column .42 and the driving columns 46 and. 47. By means of these by-pass pipes one or more of the cylinders may be put out of action without it being necessary to stop the remainder. F or example, if, as in the compressor illustrated, the uppermost stage consists of four cylinders 66, 67, 68 and 69, and the normaloutput amounts to 1000 cubic metres per hour then, should one of the four cylinders be cut out, the output will be reduced from 1000 to 750 cubic metres per hour. By cutting out, for example, two cylinders, the quantity of medium drawn in through the pipe 70 and conveyed to the point of consumption by the pipe 71 is reduced to half the normal output, i. e. to 500 cubic metresper hour.

' If, for example, the-compressor piston 52 isto be cut out then the by-pass'56 is opened. On the movement of the piston 40 in the direction of the arrow 64 the liquid displaced thereby is forced through the bypass 58 round the piston 48 so that this remains stationary whilst the piston 49 remains in operation. When the piston 40 moves in the direction of the arrow the piston 49 is forced upwards and the liquid displaced thereby is forced through the liquid column 44 so that the piston 48.-is.not actuated and remains'in its position of'rest. In the same way the remaining cylindersfmay be-brought into and outoffoperationsingly or together.

The present invention. therefore enables one or more cylinders of. a multi-stage compressor, actuated by. the same crank, to be put out of operation without stopping the remain.- der. Further, it is also. possible to control in a simple manner the output of the compressor and to make use of the-reserve sets inan eco nomical manner.

I claim:

1. In ahigh pressure reciprocating com? pressor, the combinationwith a primary piss ton effecting a positive movement, of a plurality of intermediate'pistons, an oscillating column of liquid. arranged. between: each side bypass pipe 58 into the of said primary, piston and one of saidin. V

termediate. pistons, through each of which columns power is transmittedto said intermediate pistons, uid columns, by-pass.

and" a control member. in. said 2.:In a high pressure reciprocating comuid'columns', and a control member in said by-pass. V

3. In a high pressure reciprocating compressor, the combination with a horizontally arranged primary piston eflecting'a positive movement, of a plurality of vertically arranged intermediate pistons, an oscillating column of liquid arranged between each: side of said primarypiston and one of said intermediate pistons, through each of which cola by-pass between said liq an oscillating umns power is transmitted to said intermediate pistons, an oscillating column of liquid between said intermediate pistons, a bypass between said first named liquid columns, and a control member in said by-pass.

4c. In a high pressure reciprocating compressor, the combination with a horizontally arranged primary piston effecting a positive movement, of a plurality of vertically arranged intermediate pistons, an oscillating column of liquid arranged between each side of said primary piston and one of said intermediate pistons, through each of which columns power is transmitted to said intermediate pistons, an oscillating column of liquid between said intermediate pistons, a by-pass between said first named columns and said last named columns, and a control member in said by-pass. In testimony whereof I have afiixed my signature.

CHARLES SGHAER. 

